With 4.2 million babies born yearly in the United States alone, 10% of all these newborns require some assistance to initiate breathing at birth and 1% of all these newborns require extensive resuscitation to survive. To assist medical care providers in the resuscitation of these infants, the American Academy of Pediatrics (AAP) and the American Heart Association (AHA) have developed a standardized sequential system, commonly known as the Neonatal Resuscitation Program (NRP) for evaluating a newborn and administering resuscitative measures which may include the application of pressurized oxygen, chest compressions, medications and endotracheal intubation to prevent asphyxiation, brain injury and death following birth.
In order to participate in neonatal resuscitation, a practitioner is typically enrolled in a certified NRP class which requires the memorization of clinical algorithms, passage of a written exam, and demonstration of clinical proficiency in neonatal resuscitation procedures. They are then granted a 2 year certificate attesting to their competency in performing neonatal resuscitation. NRP competency has become the standard of care for granting privileges to physicians to care for infants in hospital nurseries throughout the U.S.
Neonatal resuscitation is a complex system of procedures, decision making and medication administration based on a memorized algorithm with time constraints performed under pressure while a newborn is dying. The infant's life depends on the practitioner memorizing this algorithm, guessing the weight of an infant, counting the infant's heart rate and incorporating the appropriate procedures, medication administration and calculating appropriate device sizes and medication dosages based on approximation of the infant's weight. Presently, there are no assistive devices to measure the infant's weight, measure heart rate, calculate appropriate device sizes, calculate appropriate medication dosages, pace procedures, time procedures and medication administration and simultaneously record and create a document that represents the resuscitative effort for the medical record. In addition, the current medical culture does not provide a system to gather and analyze outcome data from present resuscitation methods for refinement.
After a baby is born (either vaginally or by cesarean section), the umbilical cord is clamped with a plastic clip and cut by a physician and handed off to another physician or nurse to be laid on a neonatal warmer for evaluation. The clamp is permanent and non-adjustable and typically crushes the tissue of the umbilical cord and is placed randomly along the cord. A theoretical clock starts upon arrival of the baby to the warmer. Within the first 30 seconds, the baby is dried, stimulated, positioned and airways are cleared of secretions with a suction device. The baby is typically evaluated for resuscitation based on three variables: breathing efficiency, heart rate, and color. However, the time to the first data acquisition of a distressed infant can range anywhere from thirty seconds to a few minutes. Moreover, the methodology for obtaining the physiological information from the infant typically involves obtaining the heart rate by squeezing the umbilical cord between the thumb and index finger and counting pulsations, using a stethoscope to listen to the lungs and an estimate or guess of neonatal weight. Such measurements are open to human error and subjectivity. If the baby is actively breathing, heart rate is greater than 100 beats per minute (BPM) and central color is pink, the baby is observed and given an evaluative score called the Apgar score at an interval of minute, 5 minutes, and 10 minutes. The infant is then returned to the mother.
On the other hand, if the baby has either poor or no respiratory effort, a heart rate less than 100 BPM or central cyanosis, a time based algorithm is enacted. Each 30 seconds the infant is re-evaluated utilizing these three criteria and a new set of procedures are performed and/or medications are administered. The baby's weight is estimated and appropriate sized devices and medication dosages are mentally calculated based on this weight estimate. Also, the physiologic data is obtained only intermittently with about thirty seconds between data points and the determination of the data is also time-consuming.
Currently the health care provider sets up the neonatal warmer equipment, resuscitation equipment, equipment settings and medications by memory usually without an assistive device. They then simultaneously evaluate the baby's respiratory effort, color, heart rate, and estimate weight and time elapsed without assistive devices.
Neonatal heart rate is typically obtained by a health care practitioner after birth by squeezing the thumb and index against the umbilical cord and counting the number of pulsations over a 6 to 30 second period. Heart rate evaluation is subjective and biased by psychological pressure placed on the practitioner to verbally state a heart rate to the team under time constraints in hopes to rapidly apply the NRP algorithm. Accuracy can be compromised by a desire for expediency. Heart rate data is manually intensive requiring one practitioner to stop all other duties and procedures while assessing heart rate.
Presently, several types of physiological assessments for infants are either not performed or are performed after several minutes of delay. For example, electrocardiogram (ECG) rhythm analysis is not performed because of the time it takes to place the leads on the infant and the poor adherence properties of adhesives on wet, greasy skin. Similarly, pulse oximetry is not universally used by many institutions within the first few minutes of resuscitation. Moreover, standards for normal oximetry values within the first minutes of life are not yet universally agreed upon and placement sites for pulse oximetry sensors have not yet been standardized. Additionally, pulse oximetry sensor signals are typically not reliable within the first 75 seconds after placement and ambient light also degrades oximeter signals. While the limbs and digits of the infant are commonly used for sensor sites, infant movement of the limbs and digits creates movement artifact leading to inaccurate measurements.
Neonatal temperature measurement is usually performed five to ten minutes after delivery. An adhesive-based probe is placed on the chest of the neonate, which has very poor adherence quality and poor signal reliability. Another measurement which is typically not routinely performed on neonates includes measurement of CO2 saturation.
Thus, the assessment and/or consideration of physiologic data is intermittent and not continuous. There are spot checks for physiologic data collection during resuscitation that interferes with the timing and flow of procedures and medication administration. However, manual physiologic data assessment creates unnecessary manpower, time and intellectual demands. The data is subjective and usually obtained under moments of stress with poor reproducibility and high noise to signal ratio. The type and quality of data that is acquired is variable from practitioner to practitioner and institution to institution. Moreover, adding to the inaccuracy of the information are the forms of data acquisition, e.g., the manual use of fingers to count pulsations in the umbilical cord or using variable qualities of stethoscopes by practitioners of variable skill levels to listen for heart tones and respiration rate.
Accordingly, medical records are presently subjective and most neonatal resuscitation records are retrospective and not recorded in real-time. When there is enough staffing to perform neonatal resuscitation, one provider is obligated as the event recorder. Tool size and medical device placement is dependent on a guess of neonatal weight and age of gestation. Procedure timing is also based on a best guess estimation of size of infant, intermittent spot physiologic data that is subjective and best estimate of time elapsed. Moreover, the time line is variable as many institutions use a viewable clock or timer. Also, the start time of the timer is also variable and is typically interrupted by the demands on practitioners to gather manually obtained physiologic data.
Medical dosages are mentally calculated during the resuscitation based on best guess of weight and correlated with best guess of time elapsed for timing of medication dosages. Oxygen blend settings are subject to the preference of the practitioner present or the institution that the resuscitation is performed in, not on specific real time neonatal physiologic data in congruence with standardized settings based on random control trial outcome data. Consequently, consistent data acquisition is given secondary priority to performing procedures on the infant.
With respect to the clamping of the umbilical cord or umbilical stump of the infant, the umbilical cord is typically clamped closed at an arbitrary location along the cord using a clothes pin-type clamp such as a Hollister Double-Grip Umbilical Cord Clamp™ (Hollister, Port Melbourne, Australia). The clamp provides hemostasis and the clamp position is fixed and permanent where the umbilical cord must be cut to remove the clamp. However, the clamp typically crushes the sight of clamping such that the tissue is crushed and the blood vessels within the umbilical cord are rendered nonviable and inaccessible. A new section of the cord must be severed to access intact umbilical vein and arteries. A second clamp is typically placed and locked on the umbilical cord and scissors are used to cut between the two clamps severing the umbilical cord in half to separate the infant from the placenta.
Frequently, the permanent clamp is placed on the umbilical cord adjacent to the fetal skin on the umbilical stump thus crushing the remaining portion of viable umbilical cord. The pediatrician caring for the infant needs a viable undamaged portion of the umbilical cord to gain access to the umbilical vessels with a plastic catheter in order to draw blood, administer medications, and administer fluids. Frequently, an inadequate portion of umbilical cord is left for the pediatrician to gain venous or arterial access to the infant.
Additionally, if the healthcare provider requires intravenous access to the infant, the umbilical cord stump is typically prepared by cutting off the permanent cord clamp and using two pairs of tweezers to thread a long pliable catheter into the umbilical vein. The length of the catheter insertion is usually estimated by the practitioner and the umbilical venous catheter is usually held in place by tying a ribbon around the umbilical cord crimping the umbilical cord around the umbilical vein catheter. This procedure is usually performed three to ten minutes into the resuscitation attempt and requires anywhere from five to fifteen minutes for correct placement of the catheter depending on the skill level of the practitioner. However, the umbilical vein catheter is prone to being positioned incorrectly and dislodged if when bumped.
Another difficulty in neonatal resuscitation is poor communication amongst the resuscitation team. Practitioners can have stethoscopes in their ears decreasing their ability to hear verbal communication by other practitioners. Physiologic data is announced verbally which can be easily ignored or unheard by entire resuscitation team. Communication can also be inhibited by practitioner hierarchy. If the leader of the resuscitation team is making inappropriate decisions or assessments, higher skilled practitioners with lower job titles tend to not communicate in order to avoid interpersonal conflict.
Accordingly, there exists a need for methods and devices for accurately assessing the physiological conditions of a newly born infant in real time and for facilitating the treatment of a distressed infant. Additionally, there also exists a need for methods and devices for clamping the umbilical cord while maintaining viable access to the cord and/or stump.